The theoretical part of this thesis describes addictive behavior on the Internet and on- line games, the profile of the target group of students in primary schools in connection with a range of personality traits in terms of posing a risk of substance use. The purpose of the research thesis is the implementation of a questionnaire study on the prevalence of addictive behavior in using the Internet to play on-line games and identify links between this behavior and the various activities carried out on the Internet, sociodemographic characteristics, experience with substance use and risk factors for anxiety, hopelessness, search experiences and impulsivity. The basic set consists of all students 6 to 9 years of school districts in Kolin and Kutna Hora. The aim is to get around the 50 respondents showing signs of addictive behavior or threat of execution dependency behavior of the correlation study, the research file contains more than 600 pupils.

The development of computer technology intervened to socio-psychological and psychiatric fields and gave rise to several types of online counseling and therapy. As the latest trends in online counseling and therapy self created applications in the textile even non textile addiction. In the Czech Republic was the first self-help application in the treatment of no cloth addiction, clinic was founded in Addictology, the first Medical Faculty of Charles University within the Internet counseling. The aim of the thesis is to evaluate the data after the first year of self-help application and to describe the demographic characteristics of users, to map incoming user self- motivated applications and types of objects the internet addiction. In the research issues the thesis deals with the analysis of demographic data, determines whether they are represented in all potential target groups, the degree of dependence on the Internet within the file, depending on what kind of Internet application in the present, and finally discovers self-help application users' motives for its use. Data analysis was carried out under conditions completely anonymous and includes both quantitative descriptive statistics and qualitative analysis. The results of socio- demographic data repelled the target group for which...

<p> <i>Impulsivity</i>, or the tendency to act prematurely without foresight, has been linked to a diverse range of pathological conditions. Foresight refers to the ability to envision future rewards and events (i.e. prospectively sample) and has been associated with decreased impulsivity. One form of impulsivity is measured by the ability to delay gratification and is often studied in the framework of Delay Discounting (DD). DD provides the means to study impulsivity in a number of pathological conditions. However, whether impulsivity precedes the development of pathological states or results from the pathological state itself is not fully understood. This necessitates an understanding of neurobiological mechanisms contributing to decision making in both non-impulsive as well as impulsive populations of individuals. </p> <p> Animal models allow invasive techniques to be used to dissect the neurocircuitry involved in decision making. Given that the decision-making process is an ongoing process rather than an isolated event, optogenetics provide the temporal and spatial specificity necessary for evaluating brain region specific contributions to decision making in DD. In the present study, optogenetics were used to assess the contribution of the medial Prefrontal Cortex (mPFC), a brain region involved in ‘goal-directed’ behavior, in the planning of future choices (i.e. prospective plans) and subsequent measures of impulsivity in an adjusting amount DD procedure. Optogenetic inhibition of mPFC was conducted in Wistar rats during different epochs of a DD task in order to assess how mPFC affects planning behavior in a population of rat not considered to be highly impulsive. Although no direct effects on planning behavior (e.g. consistency) were observed, inhibiting mPFC after a trial has been initiated and directly before a choice was made (Epoch 2) was observed to increase measures of impulsivity in comparison to days where no optogenetic manipulation occurred in a delay-specific manner. This suggests that mPFC differentially contributes to decision making at different delays. A pattern of associations between choice latency, impulsivity, and consistency began to emerge for inactivation occurring in Epoch 2, suggesting that mPFC contributes to some aspect of planning choices during this epoch. Moreover, these results indicate that mPFC is involved in decision making in Wistar Rats. Understanding the direct role that mPFC plays in promoting choices of delayed rewards provides a neurobiological target for treatment aimed at reducing impulsivity in the clinical population.</p>

Neste trabalho, nós consideramos o seguinte problema de valor inicial para uma equação diferencial funcional retardada com impulsos { \'x PONTO\' = \'varepsilon\' f (t, \'x IND.t\'), t \' DIFERENTE\' \'t IND. k\', \'DELTA\' x(\'t IND. k\') = \'varepsilon\' \' I IND. k\' (x ( \'t IND.k\')), k = 0, 1, 2, ... \'x IND. t IND.0\' = \' phi\', onde f está definida em um aberto \' OMEGA\' de R x \' G POT. -\' ([- r, 0], \' R POT. n\') e assume valores em \'R POT. n\', \' \'varepsilon\' \'G POT. - ([ - r, 0], \'R POT.n\'), r .0, onde \' G POT -\' ([ - r, 0], \' R POT. n\') denota o espaço das funções de [ - r, 0] em \' R POT. n\' que estão regradas e contínuas à esquerda. Além disso, \' t IND.0 < \' t IND. 1\'< ... \'t IND. k\' < ... são momentos pré determinados de impulsos tais que \'lim SOBRE k SETA + \' INFINITO\' \'t IND. k = + \' INFINITO\' e \'DELTA\'x (\' t IND.k\') = x ( \'t POT. + IND > k) - x (\'t IND. k). Os operadores de impulso \' I IND. k\', k = 0, 1, ... são funções contínuas de \'R POT. n\' em \' R POT. n\'. Consideramos, também, que para cada x \'varepsilon\' \' G POT. -\' ([- r, \' INFINITO\'), \'R POT. n\'), t \'SETA\' f (t, \'x IND. t\') é uma função localmente Lebesgue integrável e sua integral indefinida satisfaz uma condição do tipo Carathéodory. Além disso, f é Lipschitziana na segunda variável. Definimos \' f IND. 0\' ( \'phi\') = \' lim SOBRE T \' SETA\' \' INFINITO\' \'1 SUP. T \' INT. SUP. T INF. \' T IND.0\' f (t, \' PSI\') dt e \' I IND. 0(x) = \' lim SOBRE T \'SETA\' \' INFINITO\' \' 1 SUP. T\' \' SIGMA\' IND. 0 < ou = \' t IND. i\' < T onde \' psi\' \'varepsilon\' \' G POT. -\' ([ - r, 0], \' R POT. n\', e consideremos a seguinte equação diferencial funcioonal autônoma \" média\" y PONTO = \' varepsilon\' [ \' f IND. 0\' (\' y IND. t\' + \' I IND> 0\' (y (t))], \'y IND. t IND. 0 = \' phi\'. Então provamos que, sob certas condições, a solução x(t) de (1) se aproxima da solução y(t) de (2) em tempo assintoticamente grande / In this present work, we condider the following initial value problem for a retarded functional differential equation with impulses { \'x POINT\' = \'varepsilon\' f (t, \'x IND.t\'), t \' DIFFERENT\' \'t IND. k\', \'DELTA\' x(\'t IND. k\') = \'varepsilon\' \' I IND. k\' (x ( \'t IND.k\')), k = 0, 1, 2, ... \'x IND. t IND.0\' = \' phi\', where f está defined in a open set \' OMEGA\' de R x \' G POT. -\' ([- r, 0], \' R POT. n\'), r >0, and takes values in \'R POT. n\', \' \'varepsilon\' \'G POT. - ([ - r, 0], \'R POT.n\'), r .0, where \' G POT -\' ([ - r, 0], \' R POT. n\') denotes the space of regulated functions from [ - r, 0] to \' R POT. n\' which are left continuous. Furthermore, \' t IND.0 < \' t IND. 1\'< ... \'t IND. k\' < ... are pre-assigned moments of impulse effects such that \'lim ON k ARROW + \' THE INFINITE\' \'t IND. k = + \' THE INFINITE\' e \'DELTA\'x (\' t IND.k\') = x ( \'t POT. + IND>k) - x (\'t IND. k). The impulse operators \' I IND. k\', k = 0, 1, ... are continuous mappings from \'R POT. n\' to \' R POT. n\'. For each x \'varepsilon\' \' G POT. -\' ([- r, \' THE INFINITE\'), \'R POT. n\'), t \'ARROW\' f (t, \'x IND. t\') is locally Lebesgue integrable and its indefinite integral satisfies a Carathéodory. Moreover, f é Lipschitzian with respect to the second variable. We define \' f IND. 0\' ( \'phi\') = \' lim ON T \' ARROW\' \' THE INFINITE\' \'1 SUP. T \' INT. SUP. T INF. \' T IND.0\' f (t, \' PSI\') dt and \' I IND. 0(x) = \' lim ON T \'ARROW\' \' THE INFINITE\' \' 1 SUP. T\' \' SIGMA\' IND. 0 < or = \' t IND. i\' < T where \' psi\' \'varepsilon\' \' G POT. -\' ([ - r, 0], \' R POT. n\', and consider the \"averaged\" autonomous functional differential equation \'y PONTO = \' varepsilon\' [ \' f IND. 0\' (\' y IND. t\' + \' I IND> 0\' (y (t))], \'y IND. t IND. 0 = \' phi\'. Then we prove that, under certain conditions, the solution x(t) of (1) in aproximates the solution y(t) de (2) in an asymptotically large time interval

Introdução: o Transtorno do jogo (TJ), anteriormente classificado como transtorno do controle do impulso, está classificado hoje, no DSM-5, entre as dependências, sendo a primeira vez que se reconhece outro comportamento (apostar), além do uso de substância, como uma dependência. Evidências apontam melhoras relevantes no funcionamento físico e psicológico propiciadas pela atividade física. É desconhecido, entretanto, se um programa de exercícios físicos pode ser útil no tratamento do transtorno do jogo (TJ), devido à falta de estudos, ao tamanho reduzido das amostras e à falta de grupo controle. Objetivo: abordar essas lacunas empíricas através da realização de um ensaio clínico controlado e randomizado com um programa de exercício físico aeróbico comparado a um grupo controle ativo (alongamento), em acréscimo ao tratamento usual para TJ, para avaliação dos efeitos do exercício aeróbico nas comorbidades psiquiátricas, na impulsividade e no comportamento de jogo. Metodologia: 59 participantes com diagnóstico confirmado de TJ em início de tratamento foram designados, aleatoriamente, para uma, de duas possibilidades: grupo experimental (GE, n=32), com oito semanas de exercício físico, duas sessões de 50 minutos, cada (10 minutos de alongamento, mais 40 minutos de exercício aeróbico com intensidade moderada a intensa, ou seja, 70 a 85% da frequência cardíaca máxima estimada para a idade); ou grupo controle (GC, n=27), com sessões de alongamento de 50 minutos, duas vezes por semana, pelo mesmo período. Teste de Cooper e monitores de frequência cardíaca foram utilizados para garantir que os participantes do GE cumprissem a frequência cardíaca alvo. Avaliadores cegos ao tipo de intervenção designada analisaram os participantes, antes e depois da intervenção. O tratamento com psicoterapia e uso de medicações psiquiátricas, durante a intervenção, foram registrados para o controle estatístico. Resultados: foram observadas reduções significativas na frequência de depressão e nas comorbidades psiquiátricas em geral, em ambos os grupos, após a intervenção. O GE apresentou uma redução mais significativa das comorbidades psiquiátricas, quando comparado ao GC (razão de chances = 3,3; p=0,036), está diferença permaneceu significativa quando foi avaliado o subgrupo de indivíduos que realizaram apenas a intervenção física sem psicoterapia simultânea (n=42; razão de chances = 4,8; p=0,030). Não houve diferenças significativas entre os grupos, no uso de medicação psiquiátrica. Ambos os grupos também melhoraram, em relação à impulsividade avaliada em testagem neuropsicológica (controle inibitório e planejamento), mas não na impulsividade avaliada por autorrelato. As variáveis relacionadas ao jogo, ou seja, às apostas, prejuízo de socialização, desgaste emocional, e financeiro, e a \"fissura\" sofreram todas redução significativa ao final da intervenção, porém sem diferença entre GE e GC. Conclusão: um programa de exercício aeróbico tem um efeito significativo na redução das comorbidades psiquiátricas associadas em portadores de TJ, em tratamento. Este efeito mostrou-se independente da psicoterapia e da medicação. Portanto, o exercício físico pode ser um complemento valioso para o tratamento do TJ, por ser acessível, além de ser uma alternativa aos medicamentos psiquiátricos, ajudando as pessoas que sofrem com TJ a viverem com uma melhor qualidade de vida / Introduction: The Gambling Disorder (GD), formerly classified as the impulse control disorder, is classified today in the DSM-5 among the dependencies, being this the first time other behavior (to bet) is recognized beyond the use of substances, as a dependency. Evidences have indicated relevant improvement in the physical and psychological performance propitiated by the physical activity. Nevertheless it is unknown if a physical exercise program may be useful in the Gambling Disorder (GD) treatment, due to the lack of studies, the reduced size of the samples and the lack of control group. Objective: Approaching these empiric shorcomings through a random and controlled clinic analysis with an aerobic physical exercise program compared to an active control group (stretching) besides the usual treatment to GD, to evaluate the effects of the aerobic exercises in the psychiatric comorbidity, in the impulsiveness and in the game behavior. Methodology: Fifty-nine participants with a confirmed diagnostic in GD in the beginning of the treatment were designated randomly for one of the two possibilities : experimental group (GE, n=32), eight weeks of physical exercises, with two sections of fifty minutes each (10 minutes of stretching, plus 40 minutes of aerobic exercises with moderate to intense intensity, i.e. from 70 to 85% of the maximum cardio frequency estimated to the age; or the controll group (GC, n=27), fifty minutes stretching sessions twice a week during the same period. Cooper\'s Test and cardio-frequency monitors were used to guarantee that the participants of the GE fulfilled the cardio frequency target. Evaluators blind to the designated intervention analyzed the participants before and after the intervention. The treatment with psychotherapy and the use of psychiatric medicines during the intervention were registered for statistical control. Results: Significant reductions in the frequency of depression and the psychiatric comorbidity were observed after the intervention, generally in both groups. GE presented a more expressive reduction in the psychiatric comorbidities when compared to GC (odds ration = 3,3 : p=0,036), this difference remained meaningful when the subgroup which held only the physical intervention, without simultaneous psychotherapy was evaluated (n=42 : odds ratio = 4,8 : p=0,030). There were no meaningful differences between the groups in the use of psychiatric medication. Both groups also improved in relation to the assessed impulsiveness in neuropsychological test (planning and inhibitory control), but not in the impulsivity evaluated in self-report. The variable related to game, i.e. bets, socialization detriment, emotional and financial weakening and chink have suffered all the meaningful reductions at the end of the intervention, but without difference between GE and GC. Conclusion: An aerobic exercise program has meaningful effect in the reduction of the psychiatric comorbidities associated to GD bearer in treatment, this effect happened independently of the psychotherapy and medication. Therefore, physical exercise may be a valuable complement to GD treatment because it is approachable, besides being an alternative to the psychiatric medicaments, helping people who suffer with GD to live with a better quality of life

INTRODUÇÃO: A despeito das graves consequências comportamentais de indivíduos que sofrem de impulso sexual excessivo (ISE), estudos neuropsicológicos são incipientes e trazem resultados controversos. OBJETIVOS: Por meio de um estudo experimental com sujeitos impulsivos sexuais (pacientes) e não impulsivos sexuais (controles) objetivou-se comparar: a tomada de decisão e a flexibilidade cognitiva no estado basal de vigília (tempo \"0\"); a tomada de decisão e flexibilidade cognitiva no tempo \"0\" e pós-estímulo sexual visual (tempo \"1\") em cada grupo (pacientes e controles) e entre os grupos. MÉTODO: O estudo foi desenvolvido no Ambulatório de ISE do Instituto de Psiquiatria (IPq) do HC-FMUSP. A amostra foi constituída por 30 pacientes e 30 controles recrutados através de divulgação na mídia. Homens, brasileiros, com 18 anos ou mais, que preencheram os critérios diagnósticos para ISE (CID-10 - F 52.7) e os critérios de Goodman para dependência de sexo foram incluídos como pacientes; enquanto participantes assintomáticos e que não preencheram os critérios acima foram incluídos como controles. A investigação neuropsicológica da flexibilidade cognitiva se deu por meio da aplicação Wisconsin Card Sort Test (WCST), enquanto a avaliação da tomada de decisão se deu pela aplicação do Iowa Gambling Task (IGT) no tempo \"0\" e tempo \"1\" (após visualização de vídeo erótico por 20 minutos), respeitando um intervalo mínimo de seis meses entre os tempos. Em ambos os tempos foi aplicada a Escala de Compulsividade Sexual, e no tempo \"1\" foi aplicado o Inventário do Desejo e da Excitação Sexual. RESULTADOS: No estado basal, os pacientes apresentaram maior quantidade de respostas corretas, em relação aos controles, no teste que investiga flexibilidade cognitiva (p = 0,01). Quando comparamos o desempenho de ambos os grupos com eles mesmos entre os tempos, observamos que os controles apresentaram melhor desempenho inicial (Bloco 1) na tomada de decisão (p = 0,01), bem como apresentaram mais acertos no teste que avalia flexibilidade cognitiva (p = 0,01) no tempo \"1\". O mesmo não foi observado em relação aos pacientes. Quando comparamos as médias da diferença (tempo \"1\" - tempo \"0\"), entre os grupos, observamos também melhor desempenho dos controles em relação à quantidade de acertos (p = 0,02). CONCLUSÕES: Desde onde sabemos, este é o primeiro estudo avaliando funções executivas em impulsivos sexuais, após exposição a estímulo visual sexual. Quanto à avaliação no estado basal, os pacientes apresentaram melhores resultados na flexibilidade cognitiva, contrariando a hipótese inicial. Controles apresentaram melhores desempenhos na flexibilidade cognitiva e tomada de decisão inicial após exposição ao estímulo visual sexual, quando comparados com os resultados no estado basal. Na análise da diferença de desempenho pós-estímulo visual sexual comparado com o estado basal, entre os grupos, os controles novamente apresentaram melhor desempenho cognitivo. Tais resultados indicam escolhas iniciais menos impulsivas, e melhor flexibilidade cognitiva, após exposição ao estímulo erótico, pelos controles, sugerindo dificuldades de modulação inicial do comportamento, bem como de funções cognitivas, pelos pacientes, diante do estímulo sexual, apoiando nossas hipóteses / INTRODUCTION: Despite the serious behavioral consequences of individuals suffering from excessive sexual drive (ESD), neuropsychological studies are incipient and bring controversial results. OBJECTIVES: Through an experimental study of sexually impulsive subjects (patients) and non-sexually impulsive (control group) our aim was to compare: decision making and cognitive flexibility during basal wakefulness (Time \"0\"); decision making and cognitive flexibility at time \"0\" and after visual sexual stimulation (time \"1\") in each group (patients and control group) and among groups. METHOD: The study was developed at the ESD Clinic of the Psychiatry Institute (IPq), HC-FMUSP. The sample consisted of 30 patients and 30 people in the control group recruited through media coverage. Brazilian men, 18 years and older who met the diagnostic criteria for ISE (ICD - 10 - 52.7 F) and the Goodman criteria for addiction to sex were included as patients; while asymptomatic participants and that did not meet the above criteria were included in the control group. The neuropsychological research of the cognitive flexibility was made by applying the Wisconsin Card Sort Test (WCST), while the evaluation of the decision-making was made through the application of the Iowa Gambling Task (IGT) at time \"0\" and time \"1\" (after viewing an erotic video for 20 minutes), subject to a minimum interval of six months between times. In both times, the Sexual Compulsivity Scale was applied and to time \"1\", we applied the Sexual Arousal and Desire Inventory. RESULTS: During basal wakefulness patients presented a higher number of correct responses compared to the control group, in the test that investigates cognitive flexibility (p = 0.01). When comparing the performance of both groups to each other in between times, we found that the control group had a better initial performance (Block 1) in decision making (p = 0.01) as well as provided more correct answers in the test that evaluates cognitive flexibility (p = 0.01) at time \"1\". The same was not observed in the patients group. When comparing the average of the difference (time \"1\" - time \"0\") between the groups, we noted a better performance in the control group in what concerns the amount of correct responses (p = 0.02). CONCLUSION: As far as we know, this is the first study assessing executive functions in sexual impulsive, after exposure to sexual visual stimuli. As for the evaluation at basal wakefulness, patients presented better results regarding cognitive flexibility, opposite to the initial hypothesis. The control group presented a better performance concerning cognitive flexibility and initial decision making after exposure to sexual visual stimuli, when compared with results during basal wakefulness. When analyzing the performance difference after visual sexual stimulation compared with basal wakefulness in the two groups, the control group, once again, showed better cognitive performance. Such results indicate less impulsive initial choices and better cognitive flexibility after exposure to erotic stimulation in the control group, suggesting difficulties in the initial modulation of behavior, as well ass of cognitive functions, by patients before sexual stimulation, supporting our hypothesis

O jogo patológico é classificado como um transtorno do controle dos impulsos, que envolve a fissura e a impulsividade para jogar, causando prejuízos sociais. Estudos prévios sugeriram que o topiramato poderia ser mais eficaz do que o placebo no tratamento de alguns transtornos relacionados com impulsividade, tais como transtorno de compulsão alimentar periódico, alcoolismo e dependência de cocaína. O principal objetivo deste estudo foi verificar se o topiramato foi superior ao placebo em controlar fissura e reduzir pensamentos e comportamentos relacionados ao jogo. Método: os jogadores patológicos foram aleatoriamente distribuídos em um de dois grupos: o que recebeu topiramato (n=15) e o que recebeu placebo (n=15) por 12 semanas. Durante o estudo, todos os pacientes participaram de quatro sessões psicoeducacionais, baseadas no programa de 12 passos dos jogadores anônimos. A principal variável de desfecho foi a escala G-SAS. As demais variáveis de desfecho foram consideradas secuindárias, sendo as escalas/entrevista: Escala Yale Brown de obsessão e compulsão adaptada para jogo patológico (PG-YBOCS), Timeline Follow-Back (TFB), questionário de crença de jogadores (GBQ), escala de impulsividade de Barratt (BIS-11), escala de impressão clínica global (CGI), escala de adequação social (EAS). Nos resultados, os pacientes que receberam topiramato obtiveram melhora nos escores das escalas: G-SAS, o que implica em redução dos sintomas de fissura e abstinência; PG-YBOCS, que mostrou redução de comportamentos e obsessões relacionados ao jogo; GBQ, que demonstrou redução de crenças supersticiosas e melhora cognitiva e EAS, que mostrou melhora na qualidade de vida. A entrevista TFB mostrou maiores reduções na média de tempo e quantia de dinheiro gasto em jogo no grupo topiramato em relação ao grupo placebo. Conclusão: o uso de topiramato associado a quatro sessões psicoeducacionais foi superior ao uso de placebo associado a quatro sessões psicoeducacionais, na redução de fissura, freqüência, comportamentos, superstições, quantidade de tempo e dinheiro destinados ao jogo, com melhora na qualidade de vida / Pathological gambling is an impulse control disorder that involves craving and impulsivity to gamble and in which gambling thoughts and behaviors may cause social impairment. Previous studies suggested that topiramate could be effective in the treatment of some disorders related to impulsivity, such as binge eating disorder, alcoholism or cocaine addiction. The studys main goal was to verify if topiramate was superior to placebo in controlling craving and reducing thoughts and behaviors related to gambling. Methods: pathological gamblers were randomized to topiramate (n=15) or placebo (n=15) in a 12-week, double-blind placebo controlled trial. During the 12 weeks the patients had four sessions of a program based on the 12 steps of Anonymous Gamblers. The primary outcome measure was the Gambling Symptom Assessment Scale (G-SAS), which evaluates symptoms related to abstinence. As secondary outcome measures it was used the following scales or interviews: Yale Brown Obsessive Compulsive Scale adapted for Pathological Gambling (PG-YBOCS), Timeline Follow-Back Method (TFB), Gamblers Beliefs Questionnaire (GBQ), Barratt Impulsiveness Scale (BIS-11), Clinical Global Impression (CGI), Social Adjustment Scale (SAS). Results: There were statistic robust findings in some of the scales used in this study. The group of patients who took topiramate had improvement in the scores of the G-SAS, which implies reduction in the symptoms of craving and abstinence; PG-YBOCS, which showed reductions in the behaviors and obsessions related to gambling; GBG, which revealed reduction of superstitious thoughts and cognitive improvement, and EAS that showed improvement in the quality of life. TFB showed that the topiramate group had more reductions in the average of time and money spent on gambling than the placebo group. Conclusions: According to the results, topiramate associated with four sessions based in cognitive restructuring were superior to placebo associated with four sessions based in cognitive restructuring in reducing craving, frequency, behaviors and superstitions related to gambling, and amount of time and money used in gambling. Moreover, according to SAS, the group that took topiramate had better improvement in the quality of life than the placebo group

Impulsos são perturbações abruptas que ocorrem em curto espaço de tempo e podem ser consideradas instantâneas. E os mercados financeiros estão sujeitos a choques bruscos como mudanças de governos, quebra de empresas, entre outros. Assim, é natural considerarmos a ação de tais eventos na precificação de ativos financeiros. Nosso objetivo neste trabalho é obtermos uma formulação para a equação diferencial parcial de Black-Scholes com ação impulsiva de modo que os impulsos representem estes choques. Utilizaremos a teoria de integração não-absoluta em espaço de funções para obtenção desta formulação / Impulses describe the evolution of systems where the continuous development of a process is interrupted by abrupt changes of state. Financial markets are subject to extreme events or shocks as government changes, companies colapse, etc. Thus it seems natural to consider the action of these events in the valuation of derivative securities. The aim of this work is to obtain a formulation for the Black-Scholes equation with impulse action where the impulses can represent these shocks. We use the non-absolute integration theory in functional spaces to obtain such formulation

Este trabalho fundamenta-se no desenvolvimento e aprimoramento de metodologias para a melhor representação do aterramento elétrico sob uma análise transiente. O estudo concentrase no estabelecimento de contribuições ao estado da arte associadas à análise e modelagem de aterramento impulsivo e em altas frequências. O estudo vincula-se também à avaliação da suportabilidade de seres humanos submetidos a potenciais produzidos na superfície do solo, provenientes da corrente elétrica gerada por um surto atmosférico. A concepção das metodologias propostas baseou-se no uso do Método da Modelagem por Linhas de Transmissão em uma dimensão (TLM-1D). Destacam-se três grandes tópicos da pesquisa. O primeiro concentra-se no desenvolvimento de formulação para a inclusão do fenômeno de ionização do solo ao Método TLM-1D clássico. A formulação desenvolvida tem como característica ser uma técnica generalista, independente das propriedades do meio, dimensões do eletrodo e do surto atmosférico. O segundo foco concentra-se no aprimoramento e desenvolvimento de equacionamento analítico para a estimação de potenciais gerados na superfície do solo, originados pela corrente elétrica estabelecida sobre eletrodo de aterramento. Tal equacionamento tem grande aplicabilidade em conjunto com metodologias numéricas unidimensionais, as quais não são capazes de determinar diretamente os referidos potenciais. Por fim, a realização de estudo de suportabilidade e segurança de seres humanos em contato com eletrodos de aterramento submetidos a surto atmosférico, considerando modelo representativo baseado em circuitos elétricos, consolida o trabalho desenvolvido. / This work is based on the development and improvement of methodologies for the best representation of the electrical grounding under a transient analysis. The study concentrated on establishing contributions to the state of the art related to the analysis and modeling of impulsive and high frequencies grounding systems. The study is also associated to the evaluation of the supportability of human beings submitted to the potentials produced on the soil surface from the electric current generated by a lightning. The conception of the proposed methodology was based on the Transmission Line Modeling Method in one dimension (TLM- 1D). Three major research topics can be highlighted. The first involves the development of a formulation to include the soil ionization phenomenon in the classic TLM-1D algorithm. The developed formulation is a generalist technique, independent of the medium properties, characteristic of the electrode and lightning surge. The second aims at the improvement and development of analytical equations for estimating the generated potential on the soil surface, originated by the electric current calculated in the grounding electrode. Such equationing has great applicability in conjunction with one-dimensional numerical methods which are not able to determine such potential directly. Finally, the achievement of a supportability study and personal safety of humans in contact with the grounding electrodes subjected to a lightning, considering a representative model based on electrical circuits, consolidates the developed work.

Au cours de ces dernières années, le réseau électrique est devenu un candidat incontournable pour la transmission de données à haut débit à l’intérieur des bâtiments. De nombreuses solutions sont actuellement à l’étude afin d’optimiser ces technologies connues sous le nom Courants Porteurs en Ligne (CPL) ou PLC (Power-Line Communications). La technique MIMO (Multiple-Input Multiple-Output) a été tout récemment transposée au réseau filaire électrique pour lequel différents modes d’alimentation peuvent être envisagés entre la phase, le neutre et la terre. Dans le cadre de cette thèse, nous proposons deux contributions originales à l’étude des communications numériques sur le réseau électrique à l’intérieur des bâtiments. La première contribution concerne la modélisation du canal MIMO-PLC. En repartant d’un modèle du canal paramétrique SISO (Single-Input Single-Output) connu dans la littérature, nous proposons un modèle du canal MIMO en considérant un nouveau paramètre caractérisant la corrélation spatiale. Le modèle proposé permet de représenter fidèlement la corrélation spatiale des mesures effectuées à l’échelle européenne. La deuxième contribution concerne le bruit impulsif présent sur le réseau électrique domestique qui constitue un problème majeur dans les systèmes de communications. Nous proposons une méthode basée sur la notion de capacité de coupure afin d’optimiser le débit moyen dans les systèmes OFDM (Orthogonal Frequency Division Multiplexing) soumis aux bruits impulsifs. D’abord, nous étudions la capacité du système en fonction d’une marge de bruit fournie aux symboles transmis. Ensuite, nous déterminons l’expression analytique de la probabilité de coupure (outage) d’un symbole OFDM en fonction de cette marge, en étudiant de manière détaillée l’interaction entre l’impulsion de bruit et le symbole. A partir de ces deux calculs, nous déduisons la capacité de coupure. Puis, nous proposons une approche qui maximise l’espérance mathématique du débit reçu. Finalement, nous présentons les résultats obtenus dans le cas particulier d’une transmission à haut débit sur PLC en présence de bruits impulsifs. / In recent years, the electrical network has become an essential candidate for high-speed data transmission inside buildings. Many solutions are currently underway in order to optimize these technologies known under the name of in-home Power-Line Communications (PLC). Multiple-Input Multiple-Output (MIMO) technique has recently been transposed into power-line networks for which different signal feeding possibilities can be considered between phase, neutral and earth wires. In this thesis, we propose two original contributions to indoor broadband PLC. The first contribution concerns the MIMO-PLC channel modeling. Based on a Single-Input Single-Output (SISO) parametric channel model presented in the literature, we propose a MIMO one by considering a new parameter which characterizes the spatial correlation. The proposed model enables an accurate description of the spatial correlation of European MIMO PLC field measurements. The second contribution is related to the impulsive noise present in power-line networks which constitutes a major problem in communications systems. We propose an outage capacity approach in order to optimize the average data rate in Orthogonal Frequency Division Multiplexing (OFDM) systems affected by impulsive noise. First, we study the channel capacity as a function of a noise margin provided to the transmitted symbols. Then we determine the analytical expression of the outage probability of an OFDM symbol in terms of the noise margin, by studying in detail the interaction between the noise impulse and the symbol. Based on the two aforementioned relations, we deduce the outage capacity. Then we propose an approach that enables to maximize the average system data rate. Finally, we present the results in the particular case of indoor broadband PLC in the presence of impulsive noise.